Process and apparatus for the liquefaction of gases



Sept. 30, 1930. c. w. P. HEYLANDT 1,777,040

PROCESS AND APPARATUS FOR THE LIQUEFACTION 0F GASES Filed NOV. 29, 1927 4 W4 MW M k 0 i 7; x Z 6 4 INVQENTOR.

ALLA e vs.

lPatented Sept. 30, 1930 UITE STATES FREISSUED PATENT OFFICE CHRISTIAN WIL HELM PAUL HEYLANDT, OF LANKWITZ, GERMANY, ASSIGNOR '10 FLUGA AKTIEN- GESELLSCHAFT, OF-ST. MORITZ,,SWITZEBLAND IE'RQGIIESS ANDAPPABATUS FOR THE LIQUEFACTIOII OF GASES Application filed Ifl'ovember 29, 1927, Serial No. 236,401, and in Germany December 29, 1926.

The present invention relates to a process and apparatus for the liquefaction of gases, the principal object of the invention being to provide a process for the re-liquefaction of evaporation products resulting from the withdrawal of gases from and refilling of containers in the operation of air-liquefying plants. I

In the operation of air-liquefying plants, as for instance for obtaining pure liquid oxygen, it has been customary heretofore to draw the liquid from the air-liquefying apparatus into large storage receptacles and then to take the liquid from the latter and fill it into other containers to be used as desired. However, in order to-prevent as far as possible the escape of the gases,.the liquefied gas was kept in low-pressure gasonieters and were later compressed by means of compressors into suitable containers. The present invention has for its object the elimination of this inconvenient, undesirable and expensive man-- ner of handling the gases, by providing a process whereby all escaping gases are carried back at a suitable place to the liquefying apparatus to be reliquefied, the refrigerating capacity of the apparatus being brought to such a point that the gas on being so returned will be liquefied. Thiscan be eflected by increasing the pressure,'-for instance, from the usual 200 atmospheres to 250 atmospheres, which causes the refrigerating capacity, es-

pecially of an expansion machine, to be very much increased, so that the final temperature is decreased from 13( C. to 170 C. In this manner the complete're-liquefaction of all additional waste gases returned to the column condenser is effected and it becomes unnecessary to store such gases at the producing plant.- Moreover, the process is carried out in such manner that the refrigeration is brought to a point where, for instance in air liquefaction plants, there is a surplus of cold over and above the refrigeration potential which is normally required for liquefying the entire oxygen content of the air being treated.

In the drawings accompanying and forming part of this specification,

1 is a diagrammatic side viewof an apparatus adapted to carry out the process herein described;

Figs. 2 and 3 are similar views illustrating modified forms of apparatus.

In each of the forms here shown there is provided an air liquefying and separating column 10 which is shown in one form in de tail in Figure 1, the operating parts being encased in Figures 2 and 3 and therefore not shown. However, this column, as shown in Figure 1, is provided with a condenser 11 and an evaporator 12. Also in each of these forms there is provided a storage receptacle having an outer shell 13 within which is mounted a flask 14, spaced from the shell 13 so that the flask is surroundedby an insulating space 15 preferably of the ordinary vacuum type. In Figure 1 there is shown apipe 16 provided with avalve 17 which leads to the flask14, this flask not being shown in Figure 1 but being within the housing or casing 13. In Figures 2 and 3 there is a supply pipe 18 which leads from the liquefying column 10 and is provided with a branch 19 which communicates with a coil 20-surroundin the casing 13, branch 19 connecting with t e upperend of this coil while from'the lower end of the coil leads a pipe 21 which enters the casing 13 and connects to the lower end of a coil 22. This coil 22 surrounds the flask 14 in spaced relation thereto and leads up to the top of the flask where it is connected to an inner coil 23 wound closely around the flask and having its lower end communicating by a pipe. 24 with the top of the flask 14. Also a draw ofl pipe 25 connects the'top of the flask with the pipe 18 A valve branch extends from the pipe 16 at 26 to some form of vaporizer, of which one type is shown' last forms a valved pipe 30 leads from the apparatus 10 to a coil 31in Figure 3 which surrounds the casing 27 and communicates with a double coil. 32 surrognding a flask 33 of thesame general construction as the flask 14 and its coil.

In the form shown-in-Figure 2 the pipe 30 communicates with a coil 34 surrounding the upper part of the casing and in this casing is a flask 35. Leading from the pipe 30 in Fig: ures 2 and 3 is a valved pipe 36 which communicates with an injector 37 having an intake 38 leading to the pipe 18. In Figure 1 there is shown a pipe 39 having certain functions in common with the pipe 18 and communicating with the flasks through the pipes 40 and 41 respectively. In Figures 2 and 3 there are provided pipes 42 aifording communication from the flasks of the Vaporizers to the respective pipes 18, these pipes 42 be ing valved as shown. In Figure 1 is disclosed a portable container 43 wherewith the pipes 16 and 39 communicate while in Figures 2 and 3 there is shown a primary container 44 communicating by a valved pipe 45 with the pipe 18. In these figures there are also shown secondary containers 46 communicating by a valved pipe 47 with the pipe 36. Thus in each of the forms shown there is essentially the liquefying column, a large storage flask, a vaporizer, and other means for final storage either portable as shown in Figure 1 or stationary as shown in Fi ures 2 and 3.

V In the apparatus as s own in Figure 1 any evaporation which takes place in the tank 43 or in the storage flask in the casing 13 is returned to the column 10 where such evaporated gases are again liquefied. In Figures 2 and 3 any gases produced by evaporation in the flasks 14 passes to the tanks 44 and then according to the particular requirements of the case, by means of the injector 38 and the high pressure gases developed in. the vaporizer as at 27 or 28, together with the gases from the column 10, are caused to flow into the tanks 46, being thus stored under high pressure in these tanks so that-a gas of high pressure may be obtained from the pipe 47.

t is to be understood that liquefied gas'necessary for producing high pressure gas in the evaporator can be taken .froin the flask 14 through the pipe 18 and the valved pi e 42. Any undesired vaporization arising this process passes through the pipe 29, pipe 18 and pipe 45 into the receptacle or tank 44. Evaporation from the flask 14 passes through the several coils into the'pipe 19 and thus again to the tank 44 where storage takes place. The vaporizer in Figure 2 is what is commonly termed a. warm vaporizer and is filled from the flask 14 through the usual pipes, any undesirable vaporization pass-' ing to the tank 44 through the pipe 29, or if the valve in' this pipe be closed, into the column 10. It will be noted that in Figure 3 the vaporizer is what is commonly known as a cold va orizer and the action is similar to that previously described.

The device 28 consists substantially of a uring steel bottle or jacket with an inner thinwalled vessel 35. This inner vessel receives the. liquid, which is immediately evaporated so that in the vessel there may be produced a pressure of no less than 150 atmospheres. The high evaporating pressure whichis automatically produced in the device 28 is utilized for operating the injector 37 (Fig. 2) which is connected with the distributing system or mainfor the purpose of drawing 011 the contents of the container 44 and so that a compressed gas can be produced in the secondary containers 46 that is compressed to at least 40 atmospheres, whereas on the other hand the primary container 44 is almost completely emptied by suction and is employed for the reception of further products of evaporation from the vessel 15.

From the foregoing it will be apparent that the provision of a withdrawal flask, a reservoir for liquefied gases and a transportable storage tank for liquefied gases, all of which are connected with the liquefying and separating column by means of return pipes is an essential characteristic of an apparatus for carrying out the process described. It will also be apparent-that by this process the necessity for storing the waste gases in gasometers and later to compress them into pressure gases by the use of compressors is entire- 1y eliminated.

I claim as my invention:

1. The process of liquefying evaporation products resulting from the operation of liquefied-gas containers, which consists in returning said products into a separating and liquefying' apparatus, and increasing the pressure and refrigerating capacity of said apparatus.

2. The process of liquefying gases evaporated within closed pressure tanks, which consists in introducing said gases into a distributing system operating under different degrees of pressure, and utilizing the increased pressure resulting from the transition from the liquid to the gaseous state for raising the tension of low-pressure gases and vice versa. v

3. An apparatus for liquefying evaporation products resulting from the operation of liquefied-gas containers, comprising a gassupplying system adapted to operate under different pressures, gassifiers, pipe lines com; municating with said system .and gassifiers, injectors disposed in said ipe lines, pressure tanks connected with the high and low pressure sides of said gassifiers, and means for causing the high-pressure gases from the gassifiers to actuate said injectors thereby to reduce the pressure in the low-pressure tanks and increase the pressure in the high-pressure tanks.

. 4. An apparatus for liquefying evaporation products resulting from the operation or supplying system adapted to operate under difierent pressures, gassifiers, pipe lines communicating with sa1d system and gassifiers, injectors disposed in said pipe lines, pressure tanks connected with the high and low pressure sides of said gassifiers, means for causing the high-pressure gases from the gassifiers to actuate said in ectors thereby to reduce the pressure in the low-pressure tanks and increase the pressure in the high-pressure tanks, and means for storing up in said low-pressure tanks the gases generated in the gassifiers by natural evaporation.

5. An apparatus of the character described, comprising a gas-liquefying a paratus, a

filling flask communicating t erewith, a

storage tank for liquefied gas in communication with said filling flask and apparatus, and a movable storage tank for liquefied gas also in communication with said filling flask and apparatus.

6. An apparatus of the character described, comprising a gas-liquefying apparatus, a

liquefied-gas container and a re-fill device in communication with said apparatus, pressure tanks connected with said container, means for utilizing the automatic evaporation of the liquid contents of said container for generating high pressure in said re-fiill device, and means for utilizing said high pressure for increasing the gas pressure in some of said pressure tanks and reducing the pressure in the remainder of the tanks.

7. An apparatus of the character described, comprising a gas-liquefying apparatus, a lowpressure tank and a high-pressure tank in communication with said apparatus, pressure tanks connected with said low-pressure tank,"

the communications being such that the evaporation products from sa1d low-pressure tank are operative to generate high-pressure in said high-pressure tank, and injectors disposed between said pressure tanks and said high-pressure tank and adapted to be operated by the high-pressure generated in the latter to produce increased pressure in some of said pressure tanks and reduced pressure vin the remainder of said tanks.

In testimony whereof I have signed my name to this specification. v

CHRIS'HAN QWILHELM PAUL HEYLANDT. 

